The invention relates to apparatus for use at an end of a cable in an underwater or severe environment and comprising a connector part for connection with the cable, and to a connector for use in an underwater or severe environment.
It is known in the offshore oil and gas industry to connect up services at underwater sites such as a well head installed on the sea bed. It is known from GB-A-2 192 316 to provide an underwater electrical connector having a first part provided with a plug which houses a set of electrical contact terminals and a second part provided with a mating socket surrounding a corresponding set of electrical contact pins. The plug has a cylindrical outer surface designed to fit in the socket which is also cylindrical. In use, the second part of the connector is normally secured to a sea bed installation and the first part is mated with the second part by a diver who inserts the plug into the socket, whereby the contact pins make electrical contact with the contact terminals. In some circumstances, for example in deep water, it may be preferred to use a remotely operated vehicle (ROV) rather than a diver to make the connection.
A known apparatus for use at the end of a cable in an underwater or severe environment is disclosed in International patent application No WO92/12554. As described in this application, and shown in FIGS. 16 and 17 thereof, a plug connector part is provided at its rear with a laterally directed fitting through which a cable passes into the interior of the connector part. A handle is provided to the rear of the connector part to be gripped by a diver or ROV in order to carry the plug connector part to an already installed receptacle and make the connection. The mating procedure requires careful manipulation of the plug connector part, often in poor visibility conditions, to try and achieve alignment of the connector parts and thus successful mating. In particular the diver or ROV operator should aim to avoid angular misalignment in the axial direction and circumferential misalignment.
To assist the user in maintaining control of the orientation of the connector part, the known handle is provided with a xe2x80x9cUxe2x80x9d-shaped yoke which extends forwardly from the grip portion of the handle on either side of the rear housing of the connector part, where the cable fitting is provided, to a position in front of the cable fitting where the yoke attaches to the connector part. The attachment is by means of a support ring welded on opposite sides to the front ends of the xe2x80x9cUxe2x80x9d-shaped yoke. The support ring engages in an annular groove around the outside of a rubber washer which fits round the outer circumference of the connector part and is held between a pair of axially spaced abutment rings on the connector part.
The known support arrangement works well in that the yoke supports the connector part forwardly of the cable fitting and generally centrally of the connector part, thereby tending to balance the mass of the portion of the connector part in front of the attachment point with the combined masses of the rear of the connector part and the cable leading into the rear of the connector part. Moreover, the rubber washer allows the Connector part to tilt resiliently on the support ring relative to the axial direction by xc2x110xc2x0 and also allows relative movement in the circumferential direction, thereby facilitating connection it there is some misalignment.
There is however a problem in the support arrangement in that the yoke, support ring and rubber washer all have to be sized in accordance with the outer diameter of the connector part, so that a universal support arrangement for a range of connector part sizes is not available. This leads to inventory related costs. Further, when assembling the apparatus, because the support arrangement is in front of the cable fitting, it is necessary to mount the connector part on the handle before connecting the cable to the connector part, which is not always convenient because the handle has to be available at the start of the build process.
Viewed from a first aspect the invention provides apparatus for use at an end of a cable in an underwater or severe environment, comprising a connector part for connection with the cable and adapted to be brought axially into engagement with another connector part, the connector part having a laterally directed fitting for connecting the cable thereto, and the apparatus further comprising a handle secured to the connector part at a location rearwardly of the fitting.
Viewed from a second aspect the invention provides a connector for use in an underwater or severe environment, comprising first and second connector parts adapted to be brought axially into engagement with each other, the first connector part having a laterally directed fitting for connecting a cable thereto, and the connector further comprising a handle secured to the first connector part at a location rearwardly of the fitting.
The handle can be secured to the connector part after connecting the cable, and preferably after complete assembly of the connector part, leading to flexibility during the manufacturing process. The arrangement also avoids dependence of the handle construction on the outer diameter of the connector part and can therefore permit the same handle size to be used for a range of sizes of connector part. The inventors have found that it is possible to secure the handle to the connector part rearwardly of the cable fitting without an unacceptable loss of control of the apparatus during connector engagement.
The apparatus preferably comprises a flexible portion for providing compliance between the handle and the connector part. Thus if there is some misalignment during the engagement of the connector part with the other connector part, successful mating may he achieved without necessarily having to re-orientate the handle. The flexible portion is preferably made from a resilient material, more preferably an elastomeric material, such as rubber, e.g. nitrile rubber or hydrogenated nitrile rubber.
Various securing arrangements may be provided to the rear of the fitting. A rigid securing means may be used, particularly if compliance allowing for misalignment is provided elsewhere in the system. Where a flexible portion is provided, the connector part and the handle may both be securely attached to the flexible portion. It is however preferred to provide a more positive securing arrangement, between rigid components, with the additional use of a flexible portion to resist relative movement of the components. In preferred embodiments, the handle is secured to the connector part by securing means comprising a pin passing through a bearing such that the pin and the bearing are relatively pivotable generally about the axis of the pin, and wherein the flexible portion is arranged to resist such relative pivoting. With such an arrangement of the securing means, the handle can support the connector part cantilevering forwardly therefrom without too much bending, whilst still providing compliance.
Such securing means is believed to be inventive in its own right, and accordingly viewed from another aspect the invention provides apparatus for use at an end of a cable in an underwater or severe environment, comprising a connector part for connection with the cable and adapted to be brought axially into engagement with another connector part, and a handle secured to the connector part by securing means comprising a pin passing through a bearing such that the pin and the bearing are relatively pivotable generally about the axis of the pin, and a flexible portion arranged to resist such relative pivoting.
The pin is preferably arranged perpendicularly to the axis of the connector part. Pivoting about the pin axis then provides for angular misalignment of the connector part and the handle, i.e. tilting relative to the axial direction. Whilst this is beneficial, the pivoting is only in one plane. Preferably, therefore, the passage of the pin through the bearing is also such as to allow relative pivoting of the pin and the bearing generally about an axis perpendicular to the pin axis and to the axis of the connector part. Pivoting is then possible in at least two planes. This may for example be achieved by the pin having a diameter smaller than the diameter of a hole defined by the bearing and through which the pin passes, i.e. a loose fit of the pin in the hole. Such an arrangement can in fact allow for angular misalignment in any lateral direction, i.e. left, right, up, down or any intermediate misalignment between these.
Further compliance is preferably provided by the passage of the pin through the bearing being such as to allow relative pivoting of the pin and the bearing generally about the axis of the connector part. This can allow for rotational misalignment. Again, where the pin is arranged perpendicularly to the axis of the connector part, this may be achieved by a loose fit of the pin in a bearing hole.
The passage of the pin through the bearing may also be such as to allow relative axial movement of the pin and the bearing. The preferred arrangement of the pin fitting loosely in a bearing hole can permit such axial movement. Axial compliance is advantageous to absorb initial shock loads as the connector parts are brought together.
The various relative movements discussed above are advantageously resisted by the flexible portion, preferably in resilient manner. In a preferred arrangement, the pin is mounted by a pin support and the flexible portion is interposed between an abutment fixed in relation to the pin support and an abutment fixed in relation to the bearing.
The pin may be provided on the handle and the bearing on the connector part, but preferably the pin is provided on the connector part and the bearing is provided on the handle. This can simplify the construction of the handle, which is preferably a single casting.
It is preferred for the flexible portion to be located rearwardly of the pin.